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chestnut oak (Quercus prinus)
COMMON NAMES:
chestnut oak
rock chestnut oak
rock oak
tanbark oak
SCIENTIFIC SYNONYMS:
Quercus montana Willd.
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific name of chestnut oak is
Quercus prinus L. . It has been placed within the white oak group. In the
past, Quercus prinus was applied to swamp chestnut oak (Quercus
michauxii) and Quercus montana was applied to chestnut oak. Quercus
prinus was restored to chestnut oak by Fernald in 1950. Chestnut oak
naturally hybridizes with the following species: white oak, swamp white
oak, English oak, and post oak.
NATIVE STATUS: Native, United States.
GENERAL BOTANICAL CHARACTERISTICS: Chestnut oak is a
medium-sized, native, deciduous, monoecious tree. It is long-lived and
slow-growing. At maturity, chestnut oak is usually 65 to 80 feet (20-24 m)
tall and 20 to 30 inches (51-76 cm) in d.b.h., but on good sites it can reach
a maximum size of 100 feet (30 m) in height and 72 inches (183 cm) in
d.b.h. Seedlings initially develop a deep taproot, but saplings and larger
trees have six to ten main lateral roots extending 10 to 33 feet (3-10 m)
from the root crown. These roots occur from near the soil surface to a
depth of 36 inches (91 cm). The acorns are large.
REGENERATION PROCESSES: Seed production begins when the tree
is about 20 years old. Acorn crop sizes vary considerably from year to year
with heavy crops occurring only once every 4 to 5 years. Good crops are
dependent on spring temperature patterns. Above normal temperatures
in early April followed by subnormal temperatures in early May result in
the best acorn crops. The early warm temperatures induce the early
development of staminate flowers and increase the development of viable
pollen. The cool weather delays the pollen dispersal to coincide with
pistillate flower development, and the delay may also enhance ovary
development. A gradual increase in the temperature from early spring to
summer results in poor crops. Occasionally, a chestnut oak will produce
100 to 300 pounds (45-136 kg) of acorns, but this is rare. Often a tree
will produce less than 10 pounds (4.5 kg). Chestnut oaks generally produce
fewer acorns than other upland oak species. Dissemination is by gravity
and squirrels, although white oak group acorns are not dispersed by
squirrels to the extent that red oak group acorns are. Very few available
chestnut oak acorns were buried by gray squirrels in a study of acorn
preference. Most chestnut oak acorns germinate at day/night temperatures
of 65/50 degrees Fahrenheit (18/10 deg C). Chestnut oak germination is
enhanced by 1 inch (2-3 cm) of leaf litter, but litter deeper than 2 inches
(5 cm) is unfavorable. The germination capacity of sound acorns is 90
percent. Chestnut oak acorns absorb and retain more moisture than
acorns of other oak species. Consequently, they can germinate in dry soil.
Chestnut oak seedlings are not highly site specific because of large energy
reserves in the acorns. The roots of chestnut oak seedlings penetrate 5 to 6
inches (12.7-15.2 cm) before the unfolding of primary leaves, which are
borne on stems 2 to 3 inches (5-7.6 cm) tall. Seedling growth is slow. Ten
years after establishment, seedling were 6 inches (15 cm) in a unthinned
forest, 9 inches (24 cm) in a thinned forest, and 58 inches (146 cm) in a
clearcut.
If top-killed, chestnut oaks sprout vigorously from dormant buds at
the root crown. Sprouts grow faster than seedlings. Ten years after
clearcutting, some stump sprouts were larger than 21 feet (6.4 m) tall.
Probably 75 percent of chestnut oak reproduction in the southern
Appalachian Mountains is of sprout origin. Chestnut oak sprouting
frequency is high compared to other upland oaks. In one study in the
Virginia Piedmont, the sprouting frequency of chestnut oak was over
90 percent, regardless of season of harvest or stump diameter. Although
chestnut oak initially produces large numbers of sprouts, sprout clumps
tend towards the survival of one to three stems.
SITE CHARACTERISTICS: Chestnut oak, an upland xerophytic
species, commonly occurs on ridgetops and upper slopes. It occurs from
sea level on the coastal plain of New Jersey and Long Island, New York,
to about 4,600 feet (1,400 m) in the southern Appalachians. It can occur
on all aspects; however, it is usually on south- and west-facing upper
slopes and on north and easterly aspects in the southern Piedmont.
Chestnut oak is usually found on dry, rocky, infertile soil with a low
moisture-holding capacity (although it grows best in rich, well-drained
soils along streams). For example, in southeastern Pennsylvania, many
of the ridge sites that chestnut oak dominates have good soil moisture.
Presumably, these ridges get more precipitation than lower elevations.
It is unclear why other species are excluded from these ridgetop sites,
although its possible that more mesic species cannot endure occasional
drought, which may be more severe on these sites. The infertile rocky
soil, steep slopes, and exposed conditions may also select against other
forest species. In 51 upland hardwood stands in the Piedmont of Virginia,
chestnut oak was important on sites with low soil calcium, magnesium,
and pH. Chestnut oak forests were more likely to have exposed bedrock
(67 percent of the stands), have a higher percent cover of bare ground
by rocks (5.28 percent), and have deeper litter (1.3 inches [3.4 cm]).
Overstory associates include scarlet oak, post oak (Quercus stellata),
hickories, sweet birch (Betula lenta), yellow-poplar (Liriodendron tulip-
ifera), blackgum (Nyssa sylvatica), sweetgum (Liquidambar styraciflua),
black cherry (Prunus serotina), black walnut (Juglans nigra), red maple,
sugar maple (Acer saccharum), sourwood (Oxydendron arboreum), and
black locust (Robinia pseudoacacia). Shrub associates include blueberry
(Vaccinium spp.), dwarf chinkapin oak (Quercus prinoides), mountain-
laurel (Kalmia latifolia), Rhododendron spp., sumac (Rhus spp.), green-
brier (Smilax spp.), grape (Vitis spp.), and Ceanothus spp. Pure and
almost pure stands of chestnut oak have sparse ground vegetation.
SUCCESSIONAL STATUS: Chestnut oak is intermediate in shade
tolerance. Chestnut oak reproduction dies after a few years under a
closed canopy, but if some light penetrates to the forest floor, seedling
sprouts may persist for years. The sprouts will respond to release.
Chestnut oak is excluded from mesic sites by more rapidly growing
species including yellow-poplar, sugar maple, red maple, black cherry,
northern red oak, black oak, and white oak. Post oak, scarlet oak, and
pitch pine (Pinus rigida) are better adapted than chestnut oak to some
extremely xeric sites. In the absence of disturbance, red maple and
other shade-tolerant species will succeed old-growth chestnut oak on
good sites. Regeneration is released by gypsy moth defoliation of the
overstory canopy.
SEASONAL DEVELOPMENT: Flowers develop in the spring at the
same time as leaf development. In a 3-year study of chestnut oak in
Pennsylvania, staminate flowers usually emerged during the first week
in May, and leaves unfolded several day later. Pistillate flowers appeared
in the axils of leaves on the current year's shoots, usually 5 to 10 days
after the staminate flowers emerged. Pollen dispersal, largely controlled
by weather, usually occurs 10 to 20 days after the staminate flowers
emerge. Cool weather delays pollen dispersal. Acorns mature in one
growing season and drop from early September to early October, usually
2 to 5 weeks before the acorns of other upland oaks drop. Acorns exhibit
no dormancy and germinate in the fall. If the temperature is below 61
degrees Fahrenheit (16 deg C), shoot development is inhibited, but root
development continues. Normal shoot development resumes in the spring.
GENERAL DISTRIBUTION: Chestnut oak occurs primarily in
the Appalachian Mountains and adjacent hill country. Chestnut oak is
distributed from southwestern Maine west through New York to
extreme southern Ontario and extreme southeastern Michigan, south
through southern Indiana and extreme southern Illinois to extreme
northeastern Mississippi, east through northern Alabama to Georgia,
and north along the Piedmont to Delaware. Chestnut oak is rare on the
Southeastern Coastal Plain, but occurs along the coast in Delaware, New
Jersey, New York, and in the New England states.
SKY MEADOWS DISTRIBUTION:
Tree specimens can be found on trails marked in red.
Bleak House
Appalachian Trail/Old Trail
South Ridge/North Ridge
Gap Run
Snowden
Woodpecker Lane
Sherman's Mill
Rolling Meadows/ Lost Mountain
Fish Pond
HABITAT TYPES AND PLANT COMMUNITIES: Chestnut oak is
an important species of eastern upland deciduous and coniferous forests
and may occur in pure stands. It constitutes an important component of
the subcanopy and canopy layers of Table Mountain pine (Pinus pungens)
forests.
Because of the high mortality of American chestnut (Castanea dentata)
caused by the chestnut blight fungus (Endothia parasitica) introduced
from Asia in the early 1900's, the former Appalachian oak (Quercus spp.)
-American chestnut forest is now dominated by chestnut oak, white oak,
and northern red oak (Quercus rubra).
IMPORTANCE AND USES: Good crops of chestnut oak acorns are
infrequent, but when available the acorns are eaten by numerous upland
wildlife species, including white-tailed deer, squirrels, chipmunks, mice,
and wild turkeys. White-tailed deer occasionally browse young oak sprouts,
especially the first year after cutting or burning. The deer only take the
top few inches of the sprout unless it is extremely succulent or other food
is scarce.
Small birds and mammals, as well as insects such as bees, use chestnut oak
cavities for nesting. In a survey of 31 oak-hickory (Carya spp.) stands in
the Appalachian Mountains, a disproportionate share of cavities were in
chestnut oak.
Chestnut oak acorns are considered sweet. Gray squirrels selected pignut
hickory (Carya glabra) nuts and northern red oak acorns over chestnut oak
acorns but preferred chestnut oak acorns to those of white oak.
White-tailed deer prefer chestnut oak sprouts to seedlings. Chestnut oak
sprouts are more palatable than those of bear oak (Quercus ilicifolia).
In the past, chestnut oak performed well on mine spoils in Ohio. However,
more recent plantings of chestnut oak on mine spoils have not been as
successful. Reclamation practices mandated by federal law are often
unfavorable for oak establishment. Top-soiling practices, excess soil
compaction caused by grading, and competition from seeded herbaceous
covers reduce the growth and survival of planted oak species. Chestnut
oak did not show good height growth or survival and is not recommended
for planting on graded, top-soiled mine spoils.
Chestnut oak wood is cut and utilized as white oak lumber.